Kepler Ready for Florida

byPaul GilsteronDecember 20, 2008

The Kepler mission launches March 5, a date to circle on your calendar. Kepler may become the first instrument to detect an Earth-size planet in the habitable zone of another star, using the transit method to examine 100,000 stars in its 3.5 year mission. The 0.95-meter diameter telescope is now at Ball Aerospace & Technologies (Boulder, CO), having passed the necessary environmental tests that demonstrate its space-worthiness. And word has just come that it has also passed the necessary ‘pre-ship review’ for transit to Florida in January.

Image: An artist’s rendering of what our galaxy might look like as viewed from outside. Our sun is about 25,000 light years from galactic center. The cone illustrates the neighborhood of our galaxy that the Kepler Mission will search to find habitable planets. Credit: Jon Lomberg.

The image above, the work of the fine space artist Jon Lomberg, gives an idea of where Kepler will be looking. As always, Lomberg (creator of the gorgeous Galaxy Garden in Hawaii) manages to put things in perspective. The 100,000 stars Kepler will examine seem a vast number, but note the size of the cone covered by these observations when played out against the galactic disk. Note, too, the relatively spare star fields out in our part of the galaxy, with the tightly packed core and its teeming stellar billions not in Kepler’s view.

I wish I could catch a glimpse of the container housing Kepler somewhere along its route to Florida. When I was researching my Centauri Dreams book, I was out at the Jet Propulsion Laboratory just before Spirit and Opportunity were shipped off for launch. I’ll never forget looking at the rovers and thinking that the next time I saw them, it would be through cameras mounted on each, capturing their shadows and tire tracks in the Martian terrain. Riding a Delta II rocket into space in a mere seventy-five days, Kepler promises just as stirring an outcome, one that should give us insight into how common terrestrial worlds really are.

The Milky Way Spiral Arm Pattern
Authors: Peter Englmaier, Martin Pohl, Nicolai Bissantz
(Submitted on 18 Dec 2008)
Abstract: A complete map of the 3D distribution of molecular (CO) gas was constructed using a realistic dynamical model of the gas flow in the barred potential of the Milky Way. The map shows two prominent spiral arms starting at the bar ends connecting smoothly to the 4-armed spiral pattern observed in the atomic hydrogen gas in the outer Galaxy. Unlike previous attempts, our new map uncovers the gas distribution in the bar region of the Galaxy and the far side of the disk. For the first time, we can follow arms in gas as they pass behind the galactic centre.

…it’s amazing what we can see. Who imagined we’d know so many exoplanets in just a few short years after discovering the first? Kepler and Gaia will reveal even more, perhaps confirming the hinted statistic that 30% of stars have a super-Earth.

I’ll be keeping my fingers firmly crossed until the craft is fully commissioned 45 days after launch. Even then it’ll probably be a long wait until the first results come in. The really interesting planets will have orbits several months long at least, and their site says they’ll analyzing results for almost a decade (more if the Kepler missing is extended).

It’s amazing that they should be able to detect Earth-twins (size and orbit) up to 1000 light years away, and larger Earth-like planets up to half as far again. Let’s hope they’re out there to find!

There’s one interesting snippet of information I came across in their FAQ, which could be a bit of a downer for the follow-up TPF mission:

The systems found by the Kepler Mission to have terrestrial planets can be examined in the infrared to measure the amount of zodiacal light within each system. If large amounts of zodiacal light are common, then it may be difficult for TPF to image any planets.

Let’s hope that’s not the case, or those smart scientists and engineers find a way around the problem.

tacitus, interesting point about zodiacal light. It will be instructive to watch how these findings play against the various terrestrial planet finder designs that are out there. It may turn out that a sunshade is more effective against this problem than a straight coronagraph, but time will tell. As for mission extensions, let’s hope the money is there to extend Kepler if it starts making numerous finds.

I am greatly looking forward to the launch of this telescope. I can well imagine that if we find that extra-solar Earth-like worlds are common, NASA, the European Space Agency, Russia, China, and the like will be emboldened to renew or start their efforts to send probes to these stars and to eventually plan for manned missions to any terrestrial like planets discovered. Private enterprize and non-profits will no doubt be interested. Tau Zero Centauri Dreams and all of us who blog on your site, Paul are going to have a field day, especially if Earth-like planets are found in droves.

Regardless, the discovery of Earth-like planets in habitable zones around other stars is going to be shocking. At first, I can imagine that the global community is going to say, Wow, this is really interesting!”. As more such worlds are discovered, there is going to be a paradigm shift within the scientific and perhaps faith-based cultures wherein folks in general are going to want to discover any intellegent life of any forms that may exist on some of these planets. More research by private firms and 501C-3 non-profit organization such as Tau Zero Centuari Dreams will occur in the field of deep space propulsion techniques. NASA, the European Space Agency, Russia, China and the like will take notice of these efforts and will begine to pour money into interstellar propulsion methods research and the whole effort will jump start from there.

This prospect, almost sounds like it is too good to be true, but I have a feeling that it is true. In the spirit of Ad Astra Incrementis, I say let the fun begin.

Kepler is easily one of the most significant astronomical projects of our lifetimes. It is poised to not only explode our catalog of extra-solar planets but to give us worthwhile statistics on the abundance of planets of various types. The science and the change in perspective that will come out of this mission will be truly tremendous.

maybe the first earth-size planet discovery by COROT will be announced on this symposium

COROT have a loads to offer yet on exoplanet science, the same way will happen with Kepler… the scientist will go have loads data to be analyse on next decade

Both telescopes COROT and Kepler, and the results and comfimations of the planet discovery for this telescopes not will be so easy they will go to need many telescopes or/and many hours with very presice radial velocity to confirm the mass and nature of the object,…this is go to be a very hard job for the scientist…

my hope its the very presice radial velocity the “astro combs” of 1cm/s to confirm this planets mass…

I remember reading on the Kepler mission website some time ago that very small planets (Mars and Mercury size) will be detectable only if the mission is extended beyond the original four year lifetime. Will 3.5 years be enough time to gather/detect with reasonably high significance such bodies?

And what about COROT, has anyone heard how many planets have been found and may be announced during 2009?

The obligations of the space agencies to the public are different in the USA and in Europe. Just because COROT is not publishing huge amounts of results continuously like a NASA mission is obligated to does not mean that it is a dismal failure. Take the Hipparcos mission as an example of how things are run in Europe: the satellite operated from 1989 to 1993, the Hipparcos catalogue was completed in August 1996 and the catalogue was published by ESA in June 1997. Of course, COROT is primarily a CNES mission not an ESA one, but it seems likely that most of the interesting stuff will only come to light several years after the COROT satellite has ceased operation.

“The unanticipated level of accuracy of this raw data shows that COROT will be able to see rocky planets – perhaps even as small as Earth – and possibly provide an indication of their chemical composition. ” ESA May 2007

Spotting Earth-like planets orbiting other stars is all the rage these days. But unless you have access to a space-based telescope it’s kinda tricky.

The problem is that the reflected light from a Jupiter-sized planet is roughly 10^4 fainter than the parent star. That’s hard to spot at any time but when this is coupled with the distortion that the Earth’s atmosphere introduces, these planets become almost impossible to see.

One way around this is to use adaptive optics to smooth out distortions in the wavefront from the star system as it hits the telescope’s mirror. But these systems are expensive and the demands of higher resolution make them increasingly complex too.

Another option is to take exposures that are much shorter than the time over which the atmospheric distortion occurs. Then post processing of the image compared to the image of a reference star allows the distortion to be removed.

The trouble with this technique is that the wavefront distortion varies over the entire area of the telescope’s mirror. So this kind of processing ends up averaging the distortion rather than removing it.

Takayuki Kotani from the Observatoire de Paris in France et amis are pioneering a technique called pupil remapping that could get around this. Their idea is to place a bundle of optical fibres at the focal point of the telescope. These channel the light from each point in the mirror separately, which avoids the problem of averaging out the distortion and allows much better image processing.

They’ve tested the idea on an optical bench showing that it can achieve near theoretical performance. Installed in a decent telescope, it should allow a dynamic range of around 10^6. That will allow the detection of much fainter planets than is now possible and at a fraction of the cost of high resolution adaptive optics or space-based telescopes.

Expect to see this technique producing good results in ground-based telescopes within months.

Ref: arxiv.org/abs/0901.2165: Pupil Remapping for High Contrast Astronomy: Results From an Optical Testbed

In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For the last twelve years, this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image: Marco Lorenzi).

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